package com.hmdp.service.impl;

import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.ShopType;
import com.hmdp.mapper.ShopTypeMapper;
import com.hmdp.service.IShopTypeService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisConstants;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.List;

import static com.hmdp.utils.RedisConstants.CACHE_SHOP_TYPE_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopTypeServiceImpl extends ServiceImpl<ShopTypeMapper, ShopType> implements IShopTypeService {

    @Autowired
    private StringRedisTemplate stringRedisTemplate;


    /**
     * 查询热门商品
     * @return
     */
    @Override
    public Result getList() {
        // 从redis中查询
        String key = CACHE_SHOP_TYPE_KEY;

        String typeList = stringRedisTemplate.opsForValue().get(key);

        // 非空判断
        if (typeList != null) {
            List<ShopType> list = JSONUtil.toList(typeList, ShopType.class);
            return Result.ok(list);
        }

        // 查询数据库
        List<ShopType> list = query().orderByDesc("sort").list();

        if (list.isEmpty()) {
            return Result.fail("服务异常");
        }

        // 存入redis
        stringRedisTemplate.opsForValue().set(key, JSONUtil.toJsonStr(list));

        return Result.ok(list);
    }
}
